Synthesis, anti-inflammatory and ulcerogenicity studies of some substituted pyrimido[1,6-a]azepine derivatives

Article abstract of DOI:10.1016/j.ejmech.2010.04.005

New series of pyrimido[1,6-a]azepines were prepared through reaction of the key amino compound 4 with various reagents to give a variety of 3-N-substituted amino derivatives 5-13. The synthesized compounds included the Mannich bases 5a-c, the formimidic acid ester 6, the phenylformamidines 7a-c, the benzylidine amino derivatives 8a-c, the acetic acid derivatives 9, 10a-c and 11, the carbamoylformates 12a,b and the amides 13a,b. All compounds were screened for their anti-inflammatory activity using the carrageenan-induced paw oedema in rats using diclofenac sodium as reference drug. In addition, ulcer indices for the most active compounds were calculated. Compounds 3, 4, 8a,c, 11 and 12a, b showed activity similar to or higher than diclofenac sodium with no or minimal gastric ulceration. The most active compound with no ulcerogenic effect is the amino derivative 4 (IC 50=6.61 mmol/kg).

Full text of DOI:10.1016/j.ejmech.2010.04.005

European Journal of Medicinal Chemistry 45 (2010) 3147e3154
Contents lists available at ScienceDirect
European Journal of Medicinal Chemistry
journal homepage: http://www.elsevier.com/locate/ejmech
Original article
Synthesis, anti-inflammatory and ulcerogenicity studies of some substituted
pyrimido[1,6-a]azepine derivatives
,
b
b
Nehad A. El-Sayed a, Fadi M. Awadallah a , Nashwa A. Ibrahim , Mohammed T. El-Saadi
*
a Pharmaceutical Chemistry Department, Faculty of Pharmacy, Cairo University, Kasr-El-Eini street 11562 Cairo, Egypt
b Pharmaceutical Chemistry Department, Faculty of Pharmacy, Beni-Sweif University, 62111 Beni-Sweif, Egypt
a r t i c l e i n f o
a b s t r a c t
Article history:
New series of pyrimido[1,6-a]azepines were prepared through reaction of the key amino compound 4
with various reagents to give a variety of 3-N-substituted amino derivatives 5e13. The synthesized
compounds included the Mannich bases 5aec, the formimidic acid ester 6, the phenylformamidines
7aec, the benzylidine amino derivatives 8aec, the acetic acid derivatives 9, 10aec and 11, the carba-
moylformates 12a,b and the amides 13a,b. All compounds were screened for their anti-inflammatory
activity using the carrageenan-induced paw oedema in rats using diclofenac sodium as reference drug. In
addition, ulcer indices for the most active compounds were calculated. Compounds 3, 4, 8a,c, 11 and 12a,
b showed activity similar to or higher than diclofenac sodium with no or minimal gastric ulceration. The
most active compound with no ulcerogenic effect is the amino derivative 4 (IC 50 ¼ 6.61 mmol/kg).
Ó 2010 Elsevier Masson SAS. All rights reserved.
Received 4 March 2010
Received in revised form
1 April 2010
Accepted 8 April 2010
Available online 14 April 2010
Keywords:
Pyrimido[1,6-a]azepines
Anti-inflammatory activity
Ulcerogenicity
1. Introduction
unsubstituted derivatives [14]. Furthermore, structure extension
has been made through the introduction of additional substitutions
Inflammation is now widely appreciated in the pathogenesis of
many human diseases [1,2]. It is known not only as a symptom of
great deal of common diseases but also as an early phase of some
serious diseases such as cancer [3e5], cardiovascular diseases
[6e8] and Alzheimer’s dementia [9,10]. Thus, the discovery of novel
anti-inflammatory agents devoid of the classical non-steroidal anti-
inflammatory drugs (NSAID) toxicity, especially gastrointestinal
injury, has been attracting a lot of interest.
In the course of a research devoted to the development of new
classes of anti-inflammatory drugs, several condensed pyrimidine
derivatives have been synthesized and have shown potential
anti-inflammatory activity with good gastrointestinal safety [11,12].
These are exemplified by the pyrimido[1,6-a]azepine compounds I
and II which are few of many other structurally related derivatives
(Fig. 1) [13,14]. In the same line of research for exploring more
potent and safe anti-inflammatory agents, we have been interested
in the synthesis of the bicyclic condensed pyrimidine derivatives,
namely, pyrimido[1,6-a]azepines, possessing the more lipophilic
pyrrolidino group at position 5 as a bioisosteric replacement of the
morpholino group in compounds I and II. It is noteworthy that, as
previously reported, the presence of such substituent on the aze-
pine ring made marked improvement in activity compared to
at position 3, which have been altered to evolve our target
compounds.
2. Results and discussion
2.1. Chemistry
The synthetic pathways adopted for the preparation of the
target compounds are illustrated in Scheme 1. The known chlor-
opyrimidoazepine intermediate 2 was prepared from caprolactam
1 in several steps as previously reported [14e17]. The iminonitrile 3
was prepared by reaction of 2 with pyrrolidine. Reduction of
compound 3 with sodium borohydride afforded the key amino
nitrile 4. All target compounds were prepared through reaction of
the 3-amino function of 4 with different reagents. Thus, subjecting
compound 4 to Mannich reaction using formaldehyde and different
cyclic amines in acetonitrile afforded compounds 5aec as revealed
in their 1H NMR spectra which showed singlet in the range of
4.26e4.61 ppm attributed to the methylene protons of the NHCH2N
group, in addition to the signals assigned to the cyclic amine
groups. Moreover, compounds 7aec were synthesized via the
preparation of the precursor formimidic acid ethyl ester 6 from
compound 4 and triethyl orthoformate. This intermediate was then
condensed with various (un)substituted anilines in absolute
ethanol. The structures of 7aec were confirmed on the basis of
their elemental and spectral data. The 1H NMR spectrum of 7b
* Corresponding author. Tel.: þ20 2 26070436.
E-mail address: fadi_mae@hotmail.com (F.M. Awadallah).
0223-5234/$ e see front matter Ó 2010 Elsevier Masson SAS. All rights reserved.
doi:10.1016/j.ejmech.2010.04.005

3148
N.A. El-Sayed et al. / European Journal of Medicinal Chemistry 45 (2010) 3147e3154
was two carbon atoms apart as shown in the activity of the 3-N-
O
N
acetamido derivatives 10aec. In both series, 5aec and 10aec, the
nature of the azaheterocyclic amine was found to affect the activity
which decreased from morpholine to piperidine to pyrrolidine.
The N-phenylformamidine derivatives 7aec with different
substituted phenyl moieties revealed lower activity compared to
diclofenac sodium. The electronic nature of the substituent on the
phenyl ring seemed to affect the activity which was highest when
the ring was substituted with the electron withdrawing nitro group
7c and was lowest when there was an electron donating methoxy
group 7b. On the other hand, the N-phenylbenzylidine amino
derivatives 8aec, showed much improvement in activity compared
to their formamidine analogues 7aec and the order of activity in
relation to the electronic nature of the substituent on the phenyl
ring is maintained as in compounds 7aec.
O
CN
R
CN
H
N
OMe
NH
R'
O
N
N
N
N
O
II
O
I
R= H, morpholino
R'= C6H11, C6H5
Fig. 1. Examples of pyrimido[1,6-a]azepine derivatives with anti-inflammatory
activity.
The 3-amino acetic acid derivative 11 showed slightly higher
activity than diclofenac sodium.
The carbamoylformate derivatives 12a,b showed good activity
comparable to diclofenac and there is nearly no difference in activity
in relation to the length of the alkyl substituent in both compounds.
Finally, hybridization between the 3-aminopyrimidoazepine
structure and known anti-inflammatory drugs such as salicylic acid
as in compound 13a and diclofenac as in compound 13b resulted,
unexpectedly, in decrease in activity.
Moreover, the IC 50 values for the most active compounds 3, 4,
8c, 11 and 12a,b were calculated using doses of 12, 18, 24 mmol/kg
after 3 h from induction of inflammation (Table 2). It was found that
compounds 4 and 8c are more potent than diclofenac sodium;
having IC 50 of 6.61 and 7.14 mmol/kg, respectively.
From the results of the anti-inflammatory activity study, it was
interesting to note that the N-unsubstituted derivatives 3 and 4 are
among the most active compounds. Comparing the results inTable 1,
it could be revealed that, in general, substitutions introduced in
position 3 did not have good impact on activity, as expected, except
in few examples (8c, 11 and 12a,b). The fact that the N-substituted
derivatives may be prodrugs of the amino compound 4 and that the
ease of their biotransformation into compound 4 correlates with
their activity is an argument that needs further study.
revealed a signal at 3.86 and 8.42 ppm characteristic of the
methoxy and methylidine protons, respectively.
Furthermore, condensation of the key compound 4 with various
aromatic aldehydes was conducted in absolute ethanol in the pres-
ence of drops of glacial acetic acid to furnish the Schiff’s bases 8aec.
IR spectra of these compounds, which revealed the absence of the
amino stretching vibration bands, together with their 1H NMR
spectra confirmed the structure of the compounds. Also, reaction of
compound 4 with ethyl chloroacetate in dry acetone in the presence
of anhydrous potassium carbonate gave the intermediate ester
derivative 9 which upon condensationwith excess of the appropriate
cyclic amines afforded the amides 10aec and upon alkali hydrolysis,
the acetic acid derivative 11 was obtained. 1H NMR spectra of the
prepared compounds revealed a signal characteristic of the methy-
lene protons of the NHCH2-group, in addition to the characteristic
triplet-quartet signals of the ethyl group in 9, the signals assigned to
the protons of the cyclic amine groups in 10aec and the exchange-
able signal at 10.43 ppm of the carboxylic proton in 11.
The carbamoylformates 12a,b were prepared via condensation
of the amino compound 4 with oxalyl chloride to give an acid
chloride which was not isolated but directly reacted with methanol
or ethanol.
2.2.2. Acute ulcerogenicity study
Finally, the in situ prepared acid chlorides of salicylic acid and
diclofenac were condensed with the key intermediate 4 in dry
benzene in the presence of triethylamine to give the hybrid
derivatives 13a and 13b, respectively. The structure of the obtained
compounds was confirmed by elemental and spectral analyses.
Ulcerogenic effect of compounds 3, 4, 7c, 8c, 11 and 12a,b with
best overall profile in animal efficacy model was evaluated for
gastric ulcerogenic potential in rats (Table 3) [22,23]. When
compared to diclofenac sodium, compounds 3 and 4 did not cause
any gastric ulceration at the same dose level while the rest of the
compounds exhibited less gastric ulceration; about 24e60% that of
diclofenac sodium.
2.2. Pharmacological screening
2.2.1. Anti-inflammatory activity
3. Conclusions
Evaluation of the anti-inflammatory activity of the synthesized
compounds was performed using the carrageenan-induced rat paw
oedema model using diclofenac sodium as the reference drug
[18e21]. Mean changes in paw oedema thickness of animals pre-
treated with the tested compounds after 1, 2 and 3 h. from induc-
tion of inflammation was measured, together with the inhibition
percent of oedema by the tested compounds. The anti-inflamma-
tory activity (relative potency) of the tested compounds relative to
that of diclofenac sodium was also calculated (Table 1).
The 3-iminopyrimidoazepine derivative 3 showed slightly higher
activity compared to its reduced analogue 4 and both derivatives
revealed slightly better activity compared to diclofenac sodium.
The 3-N-substituted derivatives having saturated azaheterocyclic
amines one carbon apart from the amino group as in compounds
5aec resulted in sharp decline in the anti-inflammatory activity. The
activity was partially restored when the azaheterocyclic amino group
Various 3-substituted pyrimido[1,6-a]azepine derivatives were
synthesized and screened for their anti-inflammatory and ulcero-
genic potential. From the preliminary anti-inflammatory screening
results, it could be revealed that the most active compounds are the
3-iminopyrimidoazepine 3, its 3-amino analogue 4, the 3-N-ben-
zylidine amino compounds 8a,c, the acetic acid derivative 11 and
the carbamoylformates 12a,b which showed activity similar to or
higher than diclofenac sodium. The high activities of compounds 3
and 4 arises a question about the importance of making N-substi-
tutions and whether these N-derivatives are prodrugs of the amino
compound 4 or not.
Concerning the low ulcerogenic potential of the most active
compounds, it could be claimed that such derivatives are more
advantageous than diclofenac sodium if not in activity but at least
in gastric safety.

N.A. El-Sayed et al. / European Journal of Medicinal Chemistry 45 (2010) 3147e3154
3149
Scheme 1. Reagents and solvents: a: 1) (CH3)2SO4, 2) CH2(CN)2, 3) SO2Cl2, 4) PhNCO; b: pyrrolidine in abs.ethanol; c: NaBH4 in abs.ethanol; d: HCHO, appropriate amine in
acetonitrile; e: HC(OC2H5)3; f: AreNH2 in abs.ethanol; g: AreCHO, gl. Acetic acid, in abs.ethanol; h: ClCH2COOC2H5, anh. K2CO3 in dry acetone; i: appropriate amine; j: 5% NaOH; k:
1) (COCl)2, 2) ROH; l: RCOCl, triethylamine in dry benzene.
4. Experimental protocols
Microanalytical Center, Faculty of Science, Cairo University.
Infrared spectra were made on BRUKER Vector 22 (Japan),
infrared spectrophotometers and were expressed in wave
number (cmꢀ1) using potassium bromide disc. 1H NMR spectra
were recorded on a Varian Mercury VX-300 NMR spectrometer at
300 MHz in the specified solvent. Chemical shifts were reported
4.1. Chemistry
Melting points were uncorrected and were carried out by
open capillary tube method using IA 9100 MK-Digital Melting
Point Apparatus. Microanalyses were carried out at the
on the
d scale and were related to that of the solvent and J values

3150
N.A. El-Sayed et al. / European Journal of Medicinal Chemistry 45 (2010) 3147e3154
Table 1
Oedema thickness, inhibition percent in oedema thickness and relative potency percent of control, diclofenac sodium and tested compounds.
Comp.
Oedema thickness (ꢂ10ꢀ2 mm) ꢃ SEM (Inhibition%)
Relative potency % at 3 h
1 h
137.8 ꢃ 1.067
2 h
156.6 ꢃ 1.967
3 h
171.4 ꢃ 1.435
Control
Diclofenac sodium
3
4
5a
5b
5c
7a
7b
7c
43.20 ꢃ 1.56 (68.6)
30.50 ꢃ 2.13 (84.6)
21.20 ꢃ 1.41 (77.9)
106.21 ꢃ 3.12 (22.9)
96.81 ꢃ 2.03 (29.7)
90.801 ꢃ 1.74 (34.1)
89.20 ꢃ 1.71 (35.2)
109.41 ꢃ 2.35 (20.6)
93.61 ꢃ 1.99 (32.07)
73.64 ꢃ 1.86 (46.5)
56.41 ꢃ 1.88 (59.07)
46.81 ꢃ 2.08 (66.03)
82.63 ꢃ 1.53 (40.05)
85.40 ꢃ 2.76 (38.02)
77.21 ꢃ 1.28 (43.9)
45.12 ꢃ 2.12 (67.2)
42.40 ꢃ 2.18 (69.2)
39.62 ꢃ 2.08 (71.2)
76.21 ꢃ 1.39 (44.7)
93.81 ꢃ 2.59 (31.9)
25.80 ꢃ 1.39 (83.5)
17.60 ꢃ 1.07 (88.7)
20.41 ꢃ 1.07 (86.9)
114.80 ꢃ 2.24 (26.6)
95.72 ꢃ 2.28 (36.9)
93.30 ꢃ 1.46 (40.4)
82,20 ꢃ 2.15 (47.5)
98.23 ꢃ 2.35 (37.2)
91.61 ꢃ 2.42 (41.5)
37.61 ꢃ 2.11 (75.9)
44.40 ꢃ 2.18 (71.6)
29.82 ꢃ 1.65 (80.9)
78.62 ꢃ 1.86 (49.8)
84.43 ꢃ 2.08 (46.1)
47.20 ꢃ 2.08 (69.8)
28.65 ꢃ 2.15 (81.7)
22.41 ꢃ 1.72 (85.6)
25.61 ꢃ 2.01 (83.6)
71.22 ꢃ 1.71 (53.8)
80.65 ꢃ 1.32 (48.5)
21.09 ꢃ 1.42 (87.6)
11.28 ꢃ 1.28 (93.4)
16.92 ꢃ 1.35 (90.1)
110.80 ꢃ 0.56 (35.3)
93.20 ꢃ 1.28 (42.1)
95.20 ꢃ 2.08 (44.4)
79.32 ꢃ 3.08 (79.3)
85.20 ꢃ 18.89 (50.2)
85.6 ꢃ 1.86 (85.6)
27.42 ꢃ 1.56 (84.01)
42.41 ꢃ 2.15 (75.26)
14.23 ꢃ 1.77 (91.7)
75.11 ꢃ 1.43 (56.0)
79.60 ꢃ 2.06 (53.5)
45.40 ꢃ 1.60 (73.5)
18.42 ꢃ 1.72 (89.2)
20.01 ꢃ 1.36 (88.3)
14.43 ꢃ 0.47 (91.5)
59.32 ꢃ 1.87 (65.4)
56.22 ꢃ 2.26 (67.2)
106.62
102.85
40.29
48.05
50.68
90.52
57.30
97.71
95.90
85.91
104.68
63.93
61.07
83.90
101.82
100.79
104.45
74.65
76.71
8a
8b
8c
10a
10b
10c
11
12a
12b
13a
13b
Data analyzed by one way ANOVA (n ¼ 5), all compounds were significantly different from control using Student’s t-test, P < 0.05.
are given in Hz. 13C NMR spectra were obtained on a Varian
Mercury VX-300 NMR spectrometer at 100 MHz in the specified
solvent. Mass spectra were recorded on Fennigan MAT, SSQ 7000,
Mass spectrometer, at 70 eV (EI). IUPAC chemical nomenclature
were assigned using CS Chemdraw ultra version 5.0. Thin layer
chromatography was performed using MachereyeNagel Alugram
Sil G/UV254 silica gel plates and benzeneeethanol (9:1) as the
eluting system.
4.1.2. 3-Amino-1-oxo-2-phenyl-5-(pyrrolidin-1-yl)-1,2,4a,5,6,7,8,
9-octahydropyrimido[1,6-a] azepine-4-carbonitrile (4)
To a solution of the iminonitrile 3 (3.49 g, 10 mmol) in abso-
lute ethanol (20 ml), sodium borohydride (0.2 g, 5 mmol) was
added portion wise and stirring was continued at room temper-
ature for 1 h. The reaction mixture was left to stand overnight at
room temperature; the separated crystals were filtered, washed
with water and recrystallized from aqueous ethanol to give 2.57 g
(74%) of 4, m.p. 167e169 ꢁC. IR ymax/cmꢀ1: 3280, 3165 (NH2); 3051
(CH aromatic); 2933e2921 (CH aliphatic); 2217 (CN); 1620 (CO).
4.1.1. 3-Imino-1-oxo-2-phenyl-5-(pyrrolidin-1-yl)-1,2,3,5,6,7,8,
9-octahydropyrimido[1,6-a]azepine-4-carbonitrile (3)
1H NMR (DMSO-d6):
d 1.32 (m, CH2-7, 2H); 1.56e1.98 (m, CH2-6,
A mixture of the chloropyrimido[1,6-a]azepine 2 (3.14 g,
10 mmol) and pyrrolidine (1.06 g, 15 mmol) in absolute ethanol
(10 ml) was heated under reflux for 6 h and was evaporated
under vacuum to dryness. The remaining residue was triturated
with ether; the separated crystals were filtered and recrystallized
from aqueous ethanol, to yield 2.37 g (75%) of 3, m.p. 200e204 ꢁC.
CH2-8, eCH2CH2e pyrrolidine, 8H); 2.43 (t, J ¼ 3.2 Hz, 2CH2Ne
pyrrolidine, 4H); 3.26 (t, J ¼ 5.2 Hz, CH2-9, 2H); 3.52 (m, CH-5,
1H); 4.33 (d, J ¼ 5.5 Hz, CH-4a, 1H); 7.00e7.64 (m, aromatic
protons, 5H); 8.65 (s, NH2, 2H, which disappeared on deutera-
tion). MS, m/z (%): Mþ 351.45 (33), 210 (100). Anal. Calcd. for
C20H25N5O (351.45): C, 68.35; H, 7.17; N, 19.9.Found: C, 68.75; H,
7.32; N, 19.44.
IR ymax/cmꢀ1
(CH aliphatic); 2218 (CN); 1630 (CO). 1H NMR (CDCl3):
:
3239 (NH); 3046 (CH aromatic); 2994e2972
1.32
d
(m, CH2-7, 2H); 1.49e1.69 (m, CH2-6, CH2-8, eCH2CH2e pyrroli-
dine, 8H); 2.25 (t, J ¼ 3.2 Hz, 2CH2Ne pyrrolidine, 4H); 3.23
(t, J ¼ 5.2 Hz, CH2-9, 2H); 3.72 (m, CH-5, 1H); 7.00e7.64 (m,
aromatic protons, 5H), 8.25 (s, NH, 1H which disappeared on
deuteration). MS, m/z (%): Mþ 349 (33), 195 (100). Anal. Calcd. for
C20H23N5O (349.19): C, 68.74; H, 6.63; N, 20.04. Found: C, 68.91;
H, 6.54; N, 20.21.
4.1.3. General method for the preparation of compounds (5aec)
A mixture of the appropriate amine (10 mmol), formaldehyde
(0.3 g, 10 mmol) and acetic acid (5 ml) was added dropwise to
a stirred solution of the amino nitrile 4 (3.5 g, 10 mmol) in aceto-
nitrile (20 ml). The reaction mixture was stirred for 10 h at room
temperature; then neutralized with sodium hydroxide solution
(20% w/v) and extracted with ethyl acetate. The organic extracts
Table 3
Table 2
Ulcer index of tested compounds 3, 4, 8c, 11 and 12a,b and diclofenac sodium.
IC 50 values of the anti-inflammatory activity for compounds 3, 4, 8c, 11 and 12a,
b and diclofenac sodium.
% Incidence/10
Average no
of ulcer
Average
severity
Ulcer
index
% Inhibition in oedema thickness at
IC 50
Control
Diclofenac
sodium
e
e
e
Nil
9
(mmol/kg)
12 mmol/kg
59.50
18 mmol/kg
79.30
24 mmol/kg
88.20
6
1.2
1.8
Diclofenac
7.26
sodium
3
4
e
e
3
2
4
1
1
e
e
Nil
Nil
4.8
3.6
5.4
2.2
2.5
3
4
65.30
61.20
60.40
53.40
49.30
56.20
83.40
79.50
81.30
78.50
86.20
81.60
94.20
89.30
90.80
91.40
89.80
92.40
8.50
6.61
7.14
10.28
10.56
9.13
e
e
7c
8c
11
12a
12b
0.5
0.4
0.4
0.2
0.4
1.3
1.2
1
1
1.1
8c
11
12a
12b

N.A. El-Sayed et al. / European Journal of Medicinal Chemistry 45 (2010) 3147e3154
3151
were collected and evaporated under vacuum and the residue was
crystallized from aqueous ethanol.
4.1.5.1. N-(4-Cyano-1-oxo-2-phenyl-5-(pyrrolidin-1-yl)-1,2,4a,5,
6,7,8,9-octahydropyrimido[1,6-a]azepin-3-yl)-N-phenylformamidine
(7a). M.p. 206e210 ꢁC, yield 78.8%. IR ymax/cmꢀ1: 3350 (NH); 3057
(CH aromatic); 2912e2881 (CH aliphatic); 2225 (CN); 1650 (CO). 1H
4.1.3.1. 1-Oxo-2-phenyl-5-(pyrrolidin-1-yl)-3-[(1-pyrrolidinylmethyl)-
amino]-1,2,4a,5,6,7,8,9-octahydropyrimido[1,6-a]azepine-4-carbon-
itrile (5a). M.p. 190e195 ꢁC, yield 55.4%. IR ymax/cmꢀ1: 3295 (NH);
3056 (CH aromatic); 2925e2833 (CH aliphatic); 2220 (CN); 1650
NMR (DMSO-d6):
d 1.43 (m, CH2-7, 2H); 1.82e2.23 (m, CH2-6, CH2-
8, eCH2CH2e pyrrolidine, 8H); 2.63 (t, J ¼ 3.6 Hz, 2CH2eN pyrro-
lidine, 4H); 3.23 (t, J ¼ 5.2 Hz, CH2-9, 2H); 3.72 (m, CH-5, 1H); 4.52
(d, J ¼ 5.6 Hz CH-4a, 1H); 7.32e7.94 (m, aromatic protons, 10H);
8.62 (s, N]CHeNHe, 1H); 9.21 (s, NH, 1H, which disappeared upon
deuteration). Ms, m/z (%): Mþ 454 (53), 196 (100%). Anal. Calcd. for
C27H30N6O (454.57): C, 71.34; H, 6.65; N, 18.49. Found: C, 70.92; H,
6.61; N, 17.94.
(CO). 1H NMR (DMSO-d6):
d 1.42 (m, CH2-7, 2H); 1.93e2.21 (m,
CH2-6, CH2-8, eCH2CH2e of 2 pyrrolidine rings, 12H); 2.72 (t,
J ¼ 4.3 Hz, 2CH2eN of 2 pyrrolidine rings, 8H); 3.42 (t, J ¼ 5.1 Hz,
CH2-9, 2H); 3.92 (m, CH-5, 1H); 4.61 (s, NHeCH2eN, 2H); 4.83 (d,
J ¼ 5.4 Hz, CH-4a, 1H); 6.90e7.82 (m, aromatic protons, 5H); 9.31
(s, NH, 1H, which disappeared on deuteration). MS, m/z (%): Mþ
434 (25), 195 (100%). Anal. Calcd. for C25H34N6O (434.57): C, 69.09;
H, 7.89; N, 19.34. Found: C, 68.88; H, 7.56; N, 19.65.
4.1.5.2. N-(4-Cyano-1-oxo-2-phenyl-5-(pyrrolidin-1-yl)-1,2,4a,5,
6,7,8,9-octahydropyrimido[1,6-a]azepin-3-yl)-N-(p-methoxyphenyl)
formamidine (7b). M.p. 153e157 ꢁC, yield 65%. IR ymax/cmꢀ1: 3310
(NH); 3052 (CH aromatic); 2914e2875 (CH aliphatic); 2216 (CN);
4.1.3.2. 1-Oxo-2-phenyl-3-[(1-piperidinylmethyl)amino]-5-(pyr-
rolidin-1-yl)-1,2,4a,5,6,7,8,9-octahydropyrimido[1,6-a]azepine-4-
carbonitrile (5b). M.p. 183e189 ꢁC, yield 65%. IR ymax/cmꢀ1: 3270
(NH); 3067 (CH aromatic); 2910e2836 (CH aliphatic); 2225 (CN);
1666 (CO). 1H NMR (CDCl3):
d 1.29 (m, CH2-7, 2H); 1.64e1.93 (m,
CH2-6, CH2-8, eCH2CH2e pyrrolidine, 8H); 2.51 (t, J ¼ 4.3 Hz,
2CH2eN pyrrolidine, 4H); 3.18 (t, J ¼ 5.3 Hz, CH2-9, 2H); 3.56 (m,
CH-5, 1H); 3.86 (s, eOCH3, 3H); 4.52 (d, J ¼ 5.4 Hz, CH-4a, 1H);
7.21e7.82 (m, aromatic protons, 9H); 8.42 (s, N]CHeNH, 1H); 8.93
(s, NH, 1H, which disappeared upon deuteration). Anal. Calcd. for
C28H32N6O2 (484.59): C, 69.40; H, 6.66; N, 17.34. Found: C, 69.82; H,
6.31; N, 17.53.
1667 (CO). 1H NMR (CDCl3):
d 1.36 (m, CH2-7, 2H); 1.73e2.13 (m,
CH2-6, CH2-8, eCH2CH2e of pyrrolidine, eCH2CH2CH2e of piperi-
dine, 14H); 2.31 (t, J ¼ 4.2 Hz, 2CH2eN of piperidine, 2CH2eN of
pyrrolidine, 8H); 3.18 (t, J ¼ 5.2 Hz, CH2-9, 2H); 3.82 (m, CH-5, 1H);
4.26 (s, NHeCH2eN, 2H); 4.71 (d, J ¼ 5.7 Hz, CH-4a, 1H); 6.96e7.32
(m, aromatic protons, 5H); 8.64 (s, NH, 1H, which disappeared on
deuteration). Anal. Calcd. for C26H36N6O (448.60): C, 69.61; H, 8.09;
N, 18.73. Found: C, 69.25; H, 7.63; N, 18.43.
4.1.5.3. N-(4-Cyano-1-oxo-2-phenyl-5-(pyrrolidin-1-yl)-1,2,4a,5,6,
7,8,9-octahydropyrimido[1,6-a]azepin-3-yl)-N-(p-nitrophenyl)for-
mamidine (7c). M.p. 166e169 ꢁC, yield 71%. IR ymax/cmꢀ1: 3335
(NH); 3066 (CH aromatic); 2936e2870 (CH aliphatic); 2223 (CN);
4.1.3.3. 3-[(1-Morpholinylmethyl)amino]-1-oxo-2-phenyl-5-(pyr-
rolidin-1-yl)-1,2,4a,5,6,7,8,9-octahydropyrimido[1,6-a]azepine-4-
carbonitrile (5c). M.p. 195e199 ꢁC, yield 57%. IR ymax/cmꢀ1: 3310
(NH); 3101 (CH aromatic); 2910e2874 (CH aliphatic); 2215 (CN);
1657 (CO). 1H NMR (CDCl3):
d 1.34 (m, CH2-7, 2H); 1.68e2.13 (m,
CH2-6, CH2-8, eCH2CH2e pyrrolidine, 8H); 2.36 (t, J ¼ 4.2 Hz,
2CH2eN pyrrolidine, 4H); 3.14 (t, J ¼ 5.1 Hz, CH2-9, 2H); 3.52 (m,
CH-5, 1H); 4.62 (d, J ¼ 5.3 Hz, CH-4a, 1H); 6.82e7.64 (m, aromatic
protons, 9H); 8.61 (s, N]CHeNH, 1H); 9.32 (s, NH, 1H, which dis-
appeared upon deuteration). Anal. Calcd. for C27H29N7O3 (499.56):
C, 64.91; H, 5.85; N, 19.63. Found: C, 64.52; H, 6.34; N, 19.85.
1674 (CO). 1H NMR (CDCl3):
d 1.52 (m, CH2-7, 2H); 1.93e2.33 (m,
CH2-6, CH2-8, eCH2CH2e pyrrolidine, 8H); 2.72(t, J ¼ 4.2 Hz,
2CH2eN pyrrolidine, 2CH2eN morpholine, 8H); 3.21(t, J ¼ 5.2 Hz,
CH2-9, 2H); 3.62 (m, CH-5, 1H); 3.91 (t, J ¼ 4.2 Hz, 2CH2eO
morpholine, 4H); 4.31 (s, NHeCH2eN, 2H); 4.73(d, J ¼ 5.5 Hz, CH-
4a, 1H); 7.12e7.51 (m, aromatic protons, 5H); 9.13 (s, NH, 1H, which
disappeared on deuteration). Anal. Calcd. for C25H34N6O2 (450.27):
C, 66.64; H, 7.61; N, 18.65. Found: C, 66.31; H, 7.21; N, 19.12.
4.1.6. General procedure for the preparation of compounds (8aec)
A
mixture of the aminopyrimido[1,6-a]azepine 4 (3.5 g,
10 mmol), the appropriate benzaldehyde (12 mmol) and glacial
acetic acid (0.5 ml) in absolute ethanol (20 ml) was refluxed for
about 6 h. The mixture was concentrated and the separated crystals
were recrystallized from aqueous ethanol.
4.1.4. N-(4-Cyano-1-oxo-2-phenyl-5-(pyrrolidin-1-yl)-1,2,4a,5,
6,7,8,9-octahydropyrimido[1,6-a]azepin-3-yl)formimidic acid
ethyl ester (6)
A mixture of the amino nitrile 4 (4.36 g, 12.5 mmol), excess
triethyl orthoformate (5 ml, 15 mmol) and acetic anhydride (5
drops) was refluxed for about 10 h. The mixture was distilled under
vacuum and the crude residue was washed and crystallized from
aqueous ethanol to yield 3.21 g (73.6%) of 6, m.p. 187e189 ꢁC. IR
ymax/cmꢀ1: 3055 (CH aromatic); 2996e2930 (CH aliphatic), 2199
4.1.6.1. 3-(Benzylidineamino)-1-oxo-2-phenyl-5-(pyrrolidin-1-yl)-1,2,
4a,5,-6,7,8,9-octahydropyrimido[1,6-a]azepine-4-carbonitrile (8a).
M.p. 202e207 ꢁC, yield 75%. IR ymax/cmꢀ1: 3055 (CH aromatic);
2933e2857 (CH aliphatic), 2221 (CN); 1655 (CO). 1H NMR (DMSO-
d6):
d 1.36 (m, CH2-7, 2H); 1.58e1.93 (m, CH2-6, CH2-8, eCH2CH2e
pyrrolidine, 8H); 2.43 (t, J ¼ 4.3 Hz, 2CH2eN pyrrolidine, 4H); 3.35 (t,
J ¼ 4.9 Hz, CH2-9, 2H); 3.81 (m, CH-5, 1H); 4.51 (d, J ¼ 5.7 Hz, CH-4a,
1H); 7.00e7.64 (m, aromatic protons, 10H), 8.13 (s, eN]CHe, 1H).
Ms, m/z (%): Mþ 439 (63), 191 (100%). Anal. Calcd. for C27H29N5O
(439.55): C, 73.78; H, 6.65; N, 15.93. Found: C, 73.31; H, 6.24; N,
16.35.
(CN); 1658 (CO). 1H NMR (DMSO-d6):
d
1.12 (t, J ¼ 6.2 Hz,
eOCH2CH3, 3H); 1.43 (m, CH2-7, 2H); 1.83e2.23 (m, CH2-6, CH2-8,
eCH2CH2e pyrrolidine, 8H); 2.56 (t, J ¼ 4.6 Hz, 2CH2eN pyrrolidine,
4H); 3.41 (t, J ¼ 5.2 Hz, CH2-9, 2H); 3.84 (m, CH-5, 1H); 4.45
(q, J ¼ 6.2 Hz, eOCH2CH3, 2H); 4.82 (d, J ¼ 5.4 Hz, CH-4a, 1H); 6.72
(s, eN]CHe, 1H); 7.43e7.83 (m, aromatic protons, 5H). MS, m/z
(%): Mþ 407 (25), 161 (100%). Anal. Calcd. for C23H29N5O2 (407.23):
C, 67.79; H, 7.17; N, 17.19. Found: C, 67.35; H, 6.58; N, 17.42.
4.1.6.2. 3-(p-Methoxybenzylidineamino)-1-oxo-2-phenyl-5-(pyr-
rolidin-1-yl)-1,2,4a,5,-6,7,8,9-octahydropyrimido[1,6-a]azepine-4-
carbonitrile (8b). M.p. 185e188 ꢁC, yield 66%. IR ymax/cmꢀ1: 3041
(CH aromatic); 2920 (CH aliphatic), 2217 (CN), 1650 (CO). 1H NMR
4.1.5. General procedure for the preparation of compounds (7aec)
A mixture of the iminoether 6 (4.07 g, 10 mmol) and the
appropriate aniline (15 mmol) in absolute ethanol (15 ml) was
refluxed for 8 h. The mixture was then concentrated and the
separated crystals were recrystallized from aqueous ethanol.
(DMSO-d6):
d 1.38 (m, CH2-7, 2H); 1.62e1.96 (m, CH2-6, CH2-8,
eCH2CH2e pyrrolidine, 8H); 2.44 (t, J ¼ 3.8 Hz, 2CH2eN pyrrolidine,
4H); 3.24 (t, J ¼ 5.1 Hz, CH2-9, 2H); 3.53 (m, CH-5, 1H); 3.95
(s, eOCH3, 3H); 4.72(d, J ¼ 5.5 Hz, CH-4a,1H); 6.74e7.66 (m, aromatic

3152
N.A. El-Sayed et al. / European Journal of Medicinal Chemistry 45 (2010) 3147e3154
protons, 9H); 8.46 (s, N]CHe, 1H). Anal. Calcd. for C28H31N5O2
(469.58): C, 71.62; H, 6.65; N,14.91. Found: C, 71.23; H, 6.54; N,14.72.
3232 (NH); 3035 (CH aromatic); 2936e2918 (CH aliphatic); 2117
(CN); 1673, 1645 (2CO). 1H NMR (CDCl3):
1.45 (m, CH2-7, 2H);
1.63e1.94 (m, CH2-6, CH2-8, eCH2CH2e pyrrolidine,
d
4.1.6.3. 3-(p-Nitrobenzylidineamino)-1-oxo-2-phenyl-5-(pyrrolidin-
1-yl)-1,2,4a,5,-6,7,8,9-octahydropyrimido[1,6-a]azepine-4-carbon-
itrile (8c). M.p. 175e179 ꢁC, yield 59%. IR ymax/cmꢀ1: 3055 (CH
aromatic); 2936 (CH aliphatic), 2232 (CN), 1667 (CO). 1H NMR
eCH2CH2CH2e piperidine, 14H); 2.31 (t, J ¼ 4.3 Hz, 2CH2eN pyr-
rolidine, 4H); 3.20 (t, J ¼ 5.1 Hz, CH2-9, 2H); 3.62 (m, CH-5, 1H);
3.92 (t, J ¼ 3.6 Hz, 2CH2eN piperidine, 4H); 4.41 (s, NHeCH2eCO,
2H); 4.82 (d, J ¼ 5.2 Hz, CH-4a, 1H); 7.31e7.82 (m, aromatic
protons, 5H); 9.72 (s, NH, 1H, which disappeared upon deutera-
tion). Anal. Calcd. for C27H36N6O2 (476.61): C, 68.04; H, 7.61; N,
17.63. Found: C, 67.62; H, 7.91; N, 17.52.
(DMSO-d6):
d 1.28 (m, CH2-7, 2H); 1.65e1.91 (m, CH2-6, CH2-8,
eCH2CH2e pyrrolidine, 8H); 2.42 (t, J ¼ 5.2 Hz, 2CH2eN pyrroli-
dine, 4H); 3.19 (t, J ¼ 5.2 Hz, CH2-9, 2H); 3.52 (m, CH-5, 1H); 4.61
(d, J ¼ 5.7 Hz, CH-4a, 1H); 7.14e7.95 (m, aromatic protons, 9H);
8.69 (s, N]CHe, 1H). Anal. Calcd. for C27H28N6O3 (484.55): C,
66.93; H, 5.82; N, 17.34. Found: C, 67.21; H, 5.44; N, 16.94.
4.1.8.3. 1-Oxo-3-[(2-oxo-2-(morpholin-1-yl)ethyl)amino]-2-phenyl-
5-(pyrrolidin-1-yl)-1,2,4a,5,6,7,8,9-octahydropyrimido[1,6-a]aze-
pine-4-carbonitrile (10c). M.p. 185e188 ꢁC, yield 55%. IR ymax
/
4.1.7. (4-Cyano-1-oxo-2-phenyl-5-(pyrrolidin-1-yl)-1,2,4a,5,6,
7,8,9-octahydropyrimido[1,6-a] azepin-3-ylamino)acetic acid
ethyl ester (9)
cmꢀ1: 3217 (NH); 3080 (CH aromatic); 2993e2925 (CH aliphatic);
2220 (CN); 1660, 1617 (2CO). 1H NMR (CDCl3):
d
1.28 (m, CH2-7, 2H);
1.61e1.93 (m, CH2-6, CH2-8, eCH2CH2e pyrrolidine, 8H); 2.51 (t,
J ¼ 4.6 Hz, 2CH2eN pyrrolidine, 4H); 3.17 (t, J ¼ 5.2 Hz, CH2-9, 2H);
3.43 (m, CH-5, 1H); 3.81 (t, J ¼ 4.3 Hz, 2CH2eN morpholine,
NHeCH2eCO, 6H); 4.21 (t, J ¼ 4.3 Hz, 2CH2eO morpholine, 4H);
4.73 (d, J ¼ 5.8 Hz, CH-4a, 1H); 7.15e7.91 (m, aromatic protons, 5H);
9.17 (s, NH, 1H, which disappeared upon deuteration). Anal. Calcd.
for C26H34N6O3 (478.59): C, 65.25; H, 7.16; N, 17.58. Found: C, 64.93;
H, 7.18; N, 16.94.
A mixture of the amino nitrile 4 (3.5 g, 10 mmol), ethyl chlor-
oacetate (0.9 ml, 10 mmol) and anhydrous potassium carbonate
(1.9 g, 20 mmol), in dry acetone (15 ml) was refluxed for about 6 h
and filtered while hot. The filtrate was distilled under vacuum; the
residue was triturated with ethanol and the obtained crystals were
filtered, dried and recrystallized from aqueous ethanol to give
2.35 g (67%) of 9, m.p. 175e179 ꢁC. IR ymax/cmꢀ1: 3243 (NH); 3052
(CH aromatic); 2943e2811 (CH aliphatic); 2225 (CN); 1675, 1632
(2CO). 1H NMR (CDCl3):
d
1.22 (m, CH2-7, 2H); 1.72 (t, J ¼ 4.9 Hz,
4.1.9. (4-Cyano-1-oxo-2-phenyl-5-(pyrrolidin-1-yl)-1,2,4a,5,6,7,
8,9-octahydropyrimido[1,6-a]azepin-3-ylamino)acetic acid (11)
To a hot stirred solution of the acetic acid ethyl ester 9 (1.57 g,
3.6 mmol) in methanol (20 ml), aqueous sodium hydroxide (5%,
15 ml) was added and the mixture was refluxed with stirring for 1 h.
The solution was cooled, filtered, acidified with 6 N hydrochloric
acid; the precipitated acid was collected, washed with water and
dried. The crude product was crystallized from aqueous ethanol to
give 0.96 g (61.1%) 11, m.p. 204e208 ꢁC. IR ymax/cmꢀ1: 3260 (OH),
3120 (NH); 3061 (CH aromatic); 2932e2837 (CH aliphatic); 2230
eCH2CH3, 3H); 1.96e2.31 (m, CH2-6, CH2-8, eCH2CH2e pyrrolidine,
8H); 2.62 (t, J ¼ 4.2 Hz, 2CH2eN pyrrolidine, 4H); 3.11 (t, J ¼ 5.1 Hz,
CH2-9, 2H); 3.52 (m, CH-5, 1H); 3.82 (s, NHeCH2eCOOC2H5, 2H);
4.23 (q, J ¼ 4.8 Hz, eCH2CH3, 2H); 4.61 (d, J ¼ 5.5 Hz, CH-4a, 1H);
7.13e7.75 (m, aromatic protons, 5H); 8.93 (s, NH, 1H, which
disappeared upon deuteration). MS, m/z (%): Mþ 437 (23), 195
(100). Anal. Calcd. for C24H31N5O3 (437.24): C, 65.88; H, 7.14; N,
16.01. Found: C, 66.13; H, 7.34; N, 15.92.
4.1.8. General procedure for the preparation of compounds (10aec)
A mixture of the acetic acid ethyl ester 9 (2.18 g, 5 mmol) and the
appropriate amine (10 mmol) was refluxed for 4 h. The mixture was
then distilled under vacuum and the crude residue was crystallized
from aqueous ethanol.
(CN); 1680,1625(2CO). 1H NMR (CDCl3):
d 1.34 (m, CH2-7, 2H);
1.63e1.98 (m, CH2-6, CH2-8, eCH2CH2e pyrrolidine, 8H); 2.45 (t,
J ¼ 4.2 Hz, 2CH2eN pyrrolidine, 4H); 3.17 (t, J ¼ 5.3 Hz, CH2-9, 2H);
3.52 (m, CH-5, 1H); 4.13 (s, NHeCH2eCOOH, 2H); 4.72 (d, J ¼ 5.5 Hz,
CH-4a, 1H); 7.16e7.64 (m, aromatic protons, 5H); 9.13 (s, NH, 1H,
which disappeared upon deuteration); 10.43 (s, OH, 1H, which dis-
appeared upon deuteration). Anal. Calcd. for C22H27N5O3 (409.21): C,
64.53; H, 6.65; N, 17.10. Found: C, 64.33; H, 6.21; N, 16.83.
4.1.8.1. 1-Oxo-3-[(2-oxo-2-(pyrrolidin-1-yl)ethyl)amino]-2-phenyl-
5-(pyrrolidin-1-yl)-1,2,4a,5,6,7,8,9-octahydro-pyrimido[1,6-a]aze-
pine-4-carbonitrile (10a). M.p.155e159 ꢁC, yield 89%. IR ymax/cmꢀ1
:
3155 (NH); 3072 (CH aromatic); 2973e2953 (CH aliphatic); 2119
4.1.10. General procedure for the preparation of compounds (12a,b)
(CN); 1640, 1615 (2CO). 1H NMR (CDCl3):
d
1.25 (m, CH2-7, 2H);
A mixture of the aminopyrimido[1,6-a]azepine 4 (3.5 g,
1.67e1.98 (m, CH2-6, CH2-8, eCH2CH2e pyrrolidine at position 5,
8H); 2.25 (t, J ¼ 3.8 Hz, eCH2CH2e pyrrolidine at position 3, 4H);
2.61 (t, J ¼ 3.4 Hz, 2CH2eN pyrrolidine at position 5, 4H); 3.20
(t, J ¼ 5.2 Hz, CH2-9, 2H); 3.51 (m, CH-5, 1H); 3.92 (t, J ¼ 3.8 Hz,
NHeCH2eC]O, 2CH2eN pyrrolidine at position 3, 6H); 4.73
(d, J ¼ 5.8 Hz, CH-4a, 1H); 7.14e7.72 (m, aromatic protons, 5H); 9.55
(s, NH, 1H, which disappeared upon deuteration). 13C NMR (CDCl3):
10 mmol) and oxalyl chloride (1.9 g, 15 mmol) in dry benzene
(10 ml) were heated under reflux at a temperature 60e70 ꢁC for
about 2 h. The solvent and excess oxalyl chloride was evaporated
under reduced pressure and the residue was washed with three
portions of dry benzene (5 ml each). The appropriate alcohol
(20 ml) was added and the reaction mixture was heated under
reflux for about 2 h. The solvent was removed by distillation under
reduced pressure and the obtained residue was crystallized from
aqueous ethanol.
d
23.1 (C-7), 24.2 (eCH2CH2e pyrrolidine at position 3), 24.8
(eCH2CH2e pyrrolidine at position 5), 29.1 (C-6, C-8), 46.7
(2CH2eN pyrrolidine at position 3), 47.2 (NHeCH2eCO), 48.1 (C-9),
50.1 (C-4a), 52.3 (2CH2eN pyrrolidine at position 5), 54.2 (C-4), 65.9
(C-5), 119.3 (CN), 122.3 (C-20, C-60), 126.2 (C-40), 130.4 (C-30, C-50),
136.4 (C-10), 152.6 (C-1), 166.5 (C-3), 175.2 (NHeCH2eCO). Ms, m/z
(%): Mþ 462 (32), 195 (100). Anal. Calcd. for C26H34N6O2 (462.59): C,
67.51; H, 7.41; N, 18.17. Found: C, 67.14; H, 7.21; N, 17.85.
4.1.10.1. Methyl.4-cyano-2-phenyl-5-(pyrrolidin-1-yl)-1-oxo-1,2,4a,
5,6,7,8,9-octahydropyrimido [1,6-a]azepin-3-yl carbamoylformate
(12a). M.p. 193e195 ꢁC, yield 43%. IR ymax/cmꢀ1: 3233 (NH), 3071
(CH aromatic); 2912e2843 (CH aliphatic); 2218 (CN), 1680, 1657
(2CO). 1H NMR (CDCl3):
d 1.39 (m, CH2-7, 2H); 1.72e2.11 (m, CH2-6,
CH2-8, eCH2CH2e pyrrolidine, 8H); 2.66 (t, J ¼ 4.4 Hz, 2CH2eN
pyrrolidine, 4H); 3.34 (t, J ¼ 5.6 Hz, CH2-9, 2H); 3.82 (m, CH-5, 1H);
4.37 (s, OCH3, 3H); 4.76 (d, J ¼ 5.3 Hz, CH-4a, 1H); 7.00e7.66 (m,
aromatic protons, 5H); 8.62 (s, NH, 1H, which disappeared upon
4.1.8.2. 1-Oxo-3-[(2-oxo-2-(piperidin-1-yl)ethyl)amino]-2-phenyl-5-
(pyrrolidin-1-yl)-1,2,4a,5,6,7,8,9-octahydropyrimido[1,6-a]azepine-
4-carbonitrile (10b). M.p. 163e166 ꢁC, yield 62%. IR ymax/cmꢀ1
:

N.A. El-Sayed et al. / European Journal of Medicinal Chemistry 45 (2010) 3147e3154
3153
deuteration). 13C NMR (CDCl3):
d
22.4 (C-7), 24.4 (eCH2CH2e pyr-
The control group was given saline solution containing few drops of
Tween 80. Diclofenac sodium (20 mmol/kg) was taken as standard
drug for comparison and compounds under examination
(20 mmol/kg) were suspended in distilled water by the aid of few
drops of Tween 80 and were given intraperitoneally 1 h before
induction of inflammation. Induction of inflammation was per-
rolidine), 29.2 (C-6, C-8), 48.1 (C-9), 50.3 (2CH2eN pyrrolidine,
eOCH3), 53.6 (C-5), 55.2 (C-4a), 81.3 (C-4), 122.3 (C-20, C-60), 126.2
(C-40), 130.1 (C-30, C-50), 137.6 (C-3), 139.2 (C-10), 155.2 (C-1), 159.3
(eNHeCOeCO), 164.5 (NHeCOeCO), 167.5 (CN). Ms, m/z (%): Mþ
437 (23), 196 (100). Anal. Calcd. for C23H27N5O4 (437.49): C, 63.14;
H, 6.22; N, 16.01. Found: C, 62.92; H, 6.61; N, 15.86.
formed by S.C. injection of 50 ml of 1% carrageenanesodium gel
(SigmaeAldrich, USA), into the sub-plantar region of the right hind
paw. The dorso-ventral diameter (thickness) of the right and left
hind paw of each rat was measured using a pair of dial thickness
gauge calipers accurate to 0.001 cm 1 h, 2 h and 3 h after induction
of inflammation. The left hind paw diameter served as a control for
the degree of inflammation in the right hind paw. The percentage of
anti-inflammatory activity (% inhibition of inflammation) was
calculated according to the following equation
4.1.10.2. Ethyl.4-cyano-2-phenyl-5-(pyrrolidin-1-yl)-1-oxo-1,2,4a,5,
6,7,8,9-octahydropyrimido [1,6-a]azepin-3-yl carbamoylformate
(12b). M.p. 183e185 ꢁC, yield 55%. IR ymax/cmꢀ1: 3250 (NH) 3093
(CH aromatic); 2955e2874 (CH aliphatic); 2225 (CN); 1690, 1645
(2CO). 1H NMR (CDCl3):
d
1.16 (t, J ¼ 4.7 Hz, eCH2CH3, 3H); 1.48 (m,
CH2-7, 2H); 1.97e2.45 (m, CH2-6, CH2-8, eCH2CH2e pyrrolidine,
8H); 2.82 (t, J ¼ 4.1 Hz, 2CH2eN pyrrolidine, 4H); 3.53 (t, J ¼ 5.2 Hz,
CH2-9, 2H); 3.94 (m, CH-5, 1H); 4.42 (q, J ¼ 4.6 Hz, OCH2CH3, 2H);
4.91 (d, J ¼ 5.3 Hz, CH-4a, 1H); 7.16e7.73 (m, aromatic protons,
5H); 8.95 (s, NH, 1H, which disappeared upon deuteration). Anal.
Calcd. for C24H29N5O4 (451.52): C, 63.84; H, 6.47; N, 15.51. Found:
C, 63.92; H, 5.92; N, 15.95.
% inhibition ¼ ð1 ꢀ Lt=LcÞ ꢂ 100
Lt is the mean increase in paw thickness in rats treated with the
tested compounds.
Lc is the mean increase in paw thickness in control group.
4.1.11. General procedure for the preparation of compounds (13a,b)
A mixture of the appropriate acid (salicylic acid/diclofenac)
(15 mmol) and thionyl chloride (5 ml) was refluxed for 1 h. The
mixture was then evaporated under vacuum and the residue left
was washed 3 times with dry benzene (10 ml each). To a solution of
the residue in dry benzene (10 ml), the amino nitrile 4 (5.26 g,
15 mmol) and triethylamine (5 drops) were added and the mixture
was refluxed for 4 h. The solvent was evaporated till dryness and
the separated crystals were recrystallized from aqueous ethanol.
Data were analyzed by SPSS statistical package version 10.
Results are presented in Table 1.
4.2.2. Acute ulcerogenicity study
Adult albino rats of both sexes weighing between 120 and 150 g
were used. Animals were divided into groups each of five animals.
Rats were fasted 20 h before drug administration. The tested
compounds and diclofenac sodium were given orally in a dose of
20 mmol/kg suspended in 1% Tween while one group received
vehicle (1% Tween). Rats were fasted for 2 h, allowed to feed for 2 h
then fasted for another 20 h. Rats were given another two doses in
the second and third days. In the fourth day, rats were sacrificed,
the stomach removed, opened along with the greater curvature and
rinsed with 0.9% saline. The number of mucosal damage (red spots)
was counted and their severity (ulcerogenic severity) was graded
from 0 to 4 according to the following score assignment:
4.1.11.1. N-(4-Cyano-1-oxo-2-phenyl-5-(pyrrolidin-1-yl)-1,2,4a,5,
6,7,8,9-octahydropyrimido[1,6-a]azepin-3-yl)-2-hydroxybenzamide
(13a). M.p. 163e165 ꢁC, yield 68%. IR ymax/cmꢀ1: 3460 (OH); 3295
(NH); 3066 (CH aromatic); 2941e2912 (CH aliphatic); 2218 (CN);
1615,1655 (2CO). 1H NMR (DMSO-d6):
d 1.22 (m, CH2-7, 2H);
1.51e1.92 (m, CH2-6, CH2-8, eCH2CH2e pyrrolidine, 8H); 2.32
(t, J ¼ 3.9 Hz, 2CH2eN pyrrolidine, 4H); 3.32 (t, J ¼ 5.4 Hz, CH2-9,
2H); 3.62 (m, CH-5, 1H); 4.63 (d, J ¼ 5.9 Hz, CH-4a, 1H); 6.90e7.62
(m, aromatic protons, 9H); 8.51 (s, NH, 1H, which disappeared upon
deuteration); 10.63 (s, OH, 1H, which disappeared upon deutera-
tion). Ms, m/z (%): Mþ 471 (44), 210 (100%). Anal. Calcd. for
C27H29N5O3 (471.23): C, 68.27; H, 6.20; N, 14.85. Found: C, 67.80; H,
6.42; N, 15.21.
Score
Score
Normal (No injury)
Latent small red spot
Wide red spot
0
1
2
Slight injury
Severe injury
3
4
The following figures were calculated:
e % Incidence/10 ¼ [number of rats showing ulcer of any grade
divided by total number of rats in the group ꢂ 100]/10.
e Average number of ulcers: number of ulcers in the group/total
number of rats in the group.
e Average severity: S [each ulcer multiplied by its score of
severity]/number of ulcers in the group.
4.1.11.2. N-(4-Cyano-1-oxo-2-phenyl-5-(pyrrolidin-1-yl)-1,2,4a,5,6,7,
8,9-octahydropyrimido[1,6-a]azepin-3-yl)-2-[2-(2,6-dichlorophenyl)
amino]phenylacetamide (13b). M.p. 173e175 ꢁC, yield 59%. IR ymax
/
cmꢀ1: 3228 (NH); 3093 (CeH aromatic); 2956e2910 (CH aliphatic);
2215 (CN); 1635,1614 (2CO). 1H NMR (CDCl3):
d
1.29 (m, CH2-7, 2H);
1.74e2.21 (m, CH2-6, CH2-8, eCH2CH2e pyrrolidine, 8H); 2.53 (t,
J ¼ 4.1 Hz, 2CH2eN pyrrolidine, 4H); 3.41 (t, J ¼ 4.6 Hz, CH2-9, 2H);
3.82 (m, CH-5,1H); 4.21 (s, eCOeCH2eC6H4, 2H); 4.59 (d, J ¼ 5.7 Hz,
CH-4a, 1H); 6.50e7.64 (m, aromatic protons, 12H); 8.36 (s, NH, 1H,
which disappeared upon deuteration); 9.41 (s, NH, 1H). Anal. Calcd.
for C34H34Cl2N6O2 (629.58): C, 64.86; H, 5.44; N, 13.35. Found: C,
65.21; H, 6.13; N, 13.74.
Ulcer index ¼ the sum of the 3 figures
Results are tabulated in Table 3.
Acknowledgements
The authors are grateful to Prof. Dr. Hekma Abdl-Tawab
professor of Pharmacology Faculty of Pharmacy Cairo University for
her kind help in performing the pharmacological screening.
4.2. Pharmacological screening
4.2.1. Anti-inflammatory activity
References
Adult albino rats of both sexes weighing between 120 and 150 g
were used. Rats were uniformly hydrated by giving 3 ml water/rat
through gastric inoculation to reduce variability to oedema
response. Animals were divided into 21 groups each of five animals.
[1] C.N. Serhan, Prostaglandins Leukot. Essent. Fatty Acids 73 (2005) 141e162.
[2] X. Li, M. Zhao, Y.R. Tang, C. Wang, Z. Zhang, S. Peng, Eur. J. Med. Chem. 43
(2008) 8e18.

3154
N.A. El-Sayed et al. / European Journal of Medicinal Chemistry 45 (2010) 3147e3154
[3] M.A. Stokman, C.S. Oude-Nijhuis, F.K. Spijkervet, E.S. de Bont, P.U. Dijkastra, S.
M. Daenen, J.A. Gietema, W.T. van der Graaf, H.J. Groen, E. Vellenga, W.
A. Kamps, Cancer Invest. 24 (2006) 479e483.
[4] K.F. Foley, K.P. DeSanty, R.E. Kast, Expert Rev. Neurother. 6 (2006) 1249e1265.
[5] G. Theodoropoulos, I. Papaconstantinou, E. Felekouras, N. Nikiteas,
P. Karakitsos, D. Panoussopoulos, A.Ch. Lazaris, E. Patsouris, J. Bramis,
M. Gazouli, World J. Gastroenterol. 12 (2006) 5037e5043.
[6] H.-D. Lehmann, C. Cant, K. Hallermayer. Eur. Pat. Appl. EP 1530047, 2005.
[7] S. Omoigui, Med. Hypotheses 65 (2005) 559e569.
[13] N.M. El-Sayed, H.A. Abd-Ellatif, Bull. Fac. Pharm. Cairo University 31 (1993)
55e61.
[14] N.A. El-Sayed, A.E. Farag, M.T. El-Saadi, S.M. El-Moghazy, H.A. Abd Ellatif, Bull.
Pharm. Sci. Assiut University 29 (2006) 520e546.
[15] M.Y. Ebeid, H.H. Hassanein, N. Obidan Bull, Fac. Pharm. Cairo University 33
(1995) 35e40.
[16] M.Y. Ebeid, I. Bitter, Egypt J. Pharm. Sci. 19 (1978) 349e360.
[17] N.M. El-Sayed, M.M. Hussein, Egypt J. Pharm. Sci. 44 (2003) 319e325.
[18] C.A. Winter, E.A. Risely, G.M. Nuss, Proc. Soc. Exp. Biol. Med. 111 (1962) 544e547.
[19] Y. Kasahara, H. Hikino, S. Tsurufuji, M. Watanabe, K. Ohuchi, Planta Med. 51
(1985) 325e331.
[8] S.E. Anderson, M.-L. Edvinsson, L. Edvinsson, Clin. Sci. 105 (2003) 699e707.
[9] W.-C. Tony, Nat. Med. 12 (2006) 1005e1015.
[10] G.J. Ho, R. Drego, E. Hakimian, E. Masliah, Curr. Drug Targets Inflamm. Allergy
4 (2005) 247e256.
[20] B. Tozkoparan, E. Küpeli, E. Yes¸ ilada, M. Ertan, Bioorg. Med. Chem. 15 (2007)
1808e1814.
[11] S.M. Sondhi, N. Singh, M. Johar, A. Kumar, Bioorg. Med. Chem. 13 (2005)
6158e6166.
[21] A.M. Abdel-Megeed, H.M. Abdel-Rahman, G.-E.S. Alkaramany, M.A. El-Gendy,
Eur. J. Med. Chem. 44 (2009) 117e123.
[12] K.M. Amin, M.M. Hanna, H.E. Abo-Youssef, R.F. George, Eur. J. Med. Chem. 44
(2009) 4572e4584.
[22] M. Meshali, H. Al-Sabbagh, A. Foda, Acta Pharm. Technol. 29 (1983) 217e219.
[23] A. Robert, J.E. Nezamis, J.P. Philip, Gastroenterology 55 (1968) 481e487.